Estero De Nilahue is a coastal estuary located in the O'Higgins Region of Chile, situated in the area south of Cáhuil near the coastal town of Pichilemu. This brackish waterway winds through a landscape bordered by remnants of native forest and is closely associated with the historic salt flats (salinas) of the region. The estero flows through a low-lying coastal zone characterized by wetland habitats, making it a dynamic and ecologically rich environment. The surrounding riparian zone supports a diverse array of birdlife, including Coscoroba Swans, Black-necked Swans, coots (taguas), ducks, and herons, which are a testament to the health and productivity of the ecosystem. The waterway is navigable by small watercraft such as kayaks, offering anglers and nature enthusiasts alike a unique perspective on this relatively undisturbed coastal estuary.